This invention relates to rotational compression molding apparatus commonly used for producing plastic caps or closures for containers, such as, for example, the apparatus disclosed in U.S. Pat. No. 4,343,754, U.S. Pat. No. 4,497,765, U.S. Pat. No. 5,557,999 and U.S. Pat. No. 6,074,583, the disclosures of which are herein incorporated by reference. Such apparatus is commonly used for high volume production of plastic snap-on and screw-on caps or closures for containers for soft drinks or non-carbonated beverages, water, juices, dairy products and for some non-food containers such as oil containers. On most rotational compression molding apparatus, it is desirable or necessary to change the male and female mold components periodically in order to produce plastic closures of different designs or for replacing or repairing the mold components.
For example, in one rotational compression molding apparatus, the rotational turret supports over fifty male molds and opposing female molds which are secured to axially moveable upper and lower opposing plungers, as disclosed in the above-mentioned patents. The time required for removing and replacing all of the mold components is over four hours, and during this time, the molding machine or apparatus is not producing any plastic closures. In view of such long down time, it has been found desirable to provide the molding apparatus with a quick change tooling system for quickly removing and replacing the mold components. For example, FIGS. 11–13 of above-mentioned U.S. Pat. No. 6,074,583 disclose a laterally sliding U-shaped yoke which is carried by the supporting plunger for the female mold component, and the yoke engages diametrically opposed slots or grooves within the female mold component for retaining the mold component.